The present invention relates to an arrangement for turning, multiple stacking and aligning a paper stack.
There has already been proposed an arrangement with which printed paper stacks are taken from a printing press with low-stack unloader, are turned and can be stacked in a high-stacker. This device, when using turning stackers comprises intermediate members in the form of a rake which have to be placed between the individual paper stacks and are to be adjusted at the carrying column or carrying plate of the stacker; the rake after being placed on the paper stack etc., is held in its position by a hydraulic or mechanical interlock. Through this holding of the rake on which, after turning, the first low stack rests, the maximum possible height is available for the running in of the second stack.
It is also known that the paper stacks to be turned, e.g., for imprinting the backside of the individual sheets of this stack, must be aligned before printing on the backside in order to obtain uniform printing on the individual sheets. Since the paper stacks involve relatively large dimensions with corresponding weights, the sheets had to be aligned, up to now, by hand in partial stacks which must be taken from the overall stack; this was cumbersome and tiring for operating personnel. In order to simplify things, it has been proposed that the paper stack be vented and thus loosened from the rear side of the turning stacker, i.e., in a position turned by 90.degree., by movable nozzles. Even this venting of the paper stack had only partial success since the air supplied by the nozzles always vented only part of the paper stack one at a time so that the alignment of the sheets also was only by sections. This method only spared the personnel the strenuous alignment by hand.
For economic processing of the individual sheets, it is required that the entire stack be aligned easily and quickly and the personnel be spared any strenuous effort.
It is therefore an object of the present invention to provide a method of aligning the entire stack to be turned in its position by 90.degree..
Another object of the invention is to provide arrangements which improve the holding of the paper stacks to be turned between the carrying plates and the carrying forks of the turning stacker and to make easier the alignment of the individual sheets of the entire stack.
A further object of the present invention is to provide also an arrangement making virtually impossible the tilting of the carrying plates or carrying forks.
A still further object of the present invention is to provide an arrangement, of the foregoing character, which may be carried out with relatively few steps, and which is economical to apply.